Keratin peptides, particularly water soluble keratin peptides, are beneficial in healing damaged epithelial tissues. Unfortunately, the chemical and engineering properties of water soluble keratin peptides have been relatively limited to those achieved using oxidative and reductive chemistries. A need exists for soluble keratin peptides with a broad scope of chemical and engineering properties so that the potential applications of keratin-based materials can be expanded. Methods for chemical modification of keratin peptides are especially needed to impart desired solubility properties to the keratin peptides while maintaining the healing activity of these compounds.